Structural and thermoelastic properties of CaTiO3 perovskite between 7K and 400K

Knight, Kevin S.

doi:10.1016/j.jallcom.2011.03.014

Cited by 28 publications

(27 citation statements)

References 32 publications

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“…These displacements are found to have a linear temperature-dependence as shown in Fig. 9 Full lines show the predicted temperature-dependent bond length variations based on the parameterisation of the symmetry-adapted basis-vector magnitudes in terms of low-order polynomials [36] and are necessary to increase the length of the three short contacts from the chemically unreasonable values that the Sr 2+ cation would exhibit if it was sited on its ideal position. The correlation in vibrational behaviour between Sr and O1 probably arises from this requirement.…”

Section: Atomic Displacement Parameters and Vibrational Characteristimentioning

confidence: 67%

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Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Knight

2011

J Electroceram

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The temperature dependence of the crystal structure of the protonic conducting perovskite SrCe 0.95 Yb 0.05 O ξ (ξ∼3) has been determined from Rietveld refinement of neutron time-of-flight powder diffraction data in 25 K steps from 373 K to 1273 K. In contrast to most SrB IV O 3 perovskites which show a sequence of structural phase transitions from Pmcn -Incn -I4/mcm -Pm3m with increasing temperature, SrCe 0.95 Yb 0.05 O ξ remains orthorhombic with space group Pmcn from 4.2 K to the highest temperature measured. Crystallographic results are presented graphically in the form of the magnitude of the seven unique symmetry adapted basis vectors of a hypothetical aristotype perovskite phase. Thermoelastic properties of SrCe 0.95 Yb 0.05 O ξ deduced from the temperature variation of the unit cell volume and Debye-Waller factors are compared with literature values derived from independent calorimetric, Raman and elastic measurements. Thermodynamically, SrCe 0.95 Yb 0.05 O ξ behaves as a Debye-like solid with an average Grüneisen parameter in the range 1.4-1.5, but with two characteristic temperatures, ∼200 K and ∼600 K, the lower temperature being more related to the cation vibrations, the higher to the anion vibrations.

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Section: Atomic Displacement Parameters and Vibrational Characteristimentioning

confidence: 67%

“…A more detailed discussion of this method of data analysis is given for the example of CaTiO 3 at low temperature by Knight [36].…”

Section: Atomic Displacement Parameters and Vibrational Characteristimentioning

confidence: 99%

Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Knight

2011

J Electroceram

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“…6.65 g of LaGaO 3 powder was added to 5.88g of SrZrO 3 powder and intimately mixed using an agate pestle and mortar. The resulting mixture was placed in a standard slab sample container [32] and cooled to 11 K under 30 mbar of helium exchange gas in a Sumitomo RDK-415D top loading CCR. Powder neutron diffraction data were collected in time-of-flight from 30 ms to 130 ms using the HRPD diffractometer at the ISIS neutron spallation source.…”

Section: Experimental and Data Analysismentioning

confidence: 99%

“…These properties have direct relevance to terrestrial geophysics as the dominant mineral in the lower mantle of the Earth is the isostructural perovskite, MgSiO 3 [28][29][30][31]. In one of the few detailed low-temperature thermoelastic studies of a perovskite with this space group (CaTiO 3 ), Knight showed that to derive reliable characteristic temperatures from volumetric expansion data, that agree closely with calorimetric measurements, it is a necessary prerequisite to collect data in fine temperature increments over a wide temperature range [32]. While carrying out this parametric structural study it became apparent that providing the pseudocubic lattice parameters were well separated, it was possible to study two phases simultaneously due to the high resolution of the diffractometer that was employed.…”

Section: Introductionmentioning

confidence: 99%

Low temperature thermoelastic and structural properties of LaGaO3 perovskite in the Pbnm phase

Knight

2012

Journal of Solid State Chemistry

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“…6. The unit cell volume of the parent SrTiO 3 [13,[61][62][63] and CaTiO 3 [28,54,64] materials are shown for comparison.…”

Section: Ca-rich Materialsmentioning

confidence: 99%

Thermoelectric and structural correlations in (Sr1−x−yCaxN
Somaily
¹
,
Koleśnik
²
,
Dąbrowski
³

et al. 2017
Phys. Rev. B
6
0
4
0
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Structural and thermoelectric properties are reported for a specially designed class of A-site substituted perovskite titanates, (Sr 1-x-y Ca x Nd y )TiO 3 . Two series synthesized with various A-site Sr-rich or Ca-rich (Sr-poor) concentrations were investigated using high resolution neutron powder diffraction as a function of temperature and Nd doping. Each series was designed to have a nominally constant tolerance factor at room temperature. We determine the room temperature structures as tetragonal I4/mcm and orthorhombic Pbnm for the Sr-rich and Ca-rich series, respectively. Three low temperature orthorhombic structures, Pbnm, Ibmm and Pbcm were also observed for the Sr-rich series; whereas, the symmetry of the Ca-rich series remains unchanged throughout the full measured temperature range. Thermoelectric properties of (Sr 1-x-y Ca x Nd y )TiO 3 were investigated and correlated with the structural variables. We succeeded in achieving a relatively high figure of merit ZT=0.07 at ~400 K in the Sr-rich Sr 0.76 Ca 0.16 Nd 0.08 TiO 3 composition which is comparable to that of the best n-type TE SrTi 0.80 Nb 0.20 O 3 oxide material reported to date. For a fixed tolerance factor, the Nd doping enhances the carrier density and effective mass at the expense of the Seebeck coefficient.Thermal conductivity greatly reduces upon Nd doping in the Ca-rich series. With an enhanced Seebeck coefficient at elevated temperatures and reduced thermal conductivity, we predict that Sr 0.76 Ca 0.16 Nd 0.08 TiO 3 and similar compositions have the potential to become some of the best materials in their class of thermoelectric oxides.

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Structural and thermoelastic properties of CaTiO3 perovskite between 7K and 400K

Cited by 28 publications

References 32 publications

Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Low temperature thermoelastic and structural properties of LaGaO3 perovskite in the Pbnm phase

Thermoelectric and structural correlations in (Sr1−x−yCaxN
Somaily
¹
,
Koleśnik
²
,
Dąbrowski
³

et al. 2017
Phys. Rev. B
6
0
4
0
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Structural and thermoelastic properties of CaTiO3 perovskite between 7K and 400K

Cited by 28 publications

References 32 publications

Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Structural and thermoelastic study of the protonic conducting perovskite SrCe0.95Yb0.05Oξ (ξ ∼ 3) between 373 K and 1273 K

Low temperature thermoelastic and structural properties of LaGaO3 perovskite in the Pbnm phase

Thermoelectric and structural correlations in (Sr1−x−yCaxNSomaily1, Koleśnik2, Dąbrowski3 et al. 2017Phys. Rev. B6040View full textAdd to dashboardCite

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Product

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About

Thermoelectric and structural correlations in (Sr1−x−yCaxN
Somaily
¹
,
Koleśnik
²
,
Dąbrowski
³

et al. 2017
Phys. Rev. B
6
0
4
0
View full text Add to dashboard Cite